Nice work, i ever had the same idea, but i very lazy to work 
EDIT: i dont know why do you operate two drawtext separately
local function DrawText3DMarker(x,y,z,text)
local onScreen,_x,_y=World3dToScreen2d(x,y,z)
if onScreen then
SetTextScale(0.3, 0.3)
SetTextFont(0)
SetTextProportional(1)
SetTextColour(255, 255, 255, 255)
SetTextDropshadow(0, 0, 0, 0, 55)
SetTextEdge(2, 0, 0, 0, 150)
SetTextDropShadow()
SetTextOutline()
SetTextEntry("STRING")
SetTextCentre(1)
AddTextComponentString(text)
DrawText(_x,_y)
end
end
local function round(num, idp)
if idp and idp>0 then
local mult = 10^idp
return math.floor(num * mult + 0.5) / mult
end
return math.floor(num + 0.5)
end
--> No need native to check the distance with this :
local square = math.sqrt
local function getDistance(a, b)
local x, y, z = a.x-b.x, a.y-b.y, a.z-b.z
return square(x*x+y*y+z*z)
end
Citizen.CreateThread(function()
while true do
if --[[not--]] IsRadarEnabled() then --> With this new condition it will show you your marker only if the mini-map is disabled.
local waypoint = GetFirstBlipInfoId(8)
if DoesBlipExist(waypoint) then
local myPos = GetEntityCoords(GetPlayerPed(-1))
local coord = Citizen.InvokeNative(0xFA7C7F0AADF25D09, waypoint, Citizen.ResultAsVector())
local distance = getDistance(myPos, coord)
if distance > 999 then
roundOverKm = round(distance) * math.pow(10, -3) --> Thanks to RAMEX_DELTA_GTA for his help.
DrawText3DMarker(coord.x, coord.y, myPos.z, 'V\n' .. roundOverKm.. " kilometres")
--DrawText3DTest(coord.x, coord.y, myPos.z + 2, roundOverKm.. " kilomètres")
elseif distance > 0.1 and distance <= 999 then
DrawText3DMarker(coord.x, coord.y, myPos.z, 'V\n' .. round(distance).. " m")
--DrawText3DTest(coord.x, coord.y, myPos.z, round(distance).. " m")
end
end
end
Citizen.Wait(0)
end
end)
